1. Field of the Invention
The apparatus of the present invention relates to lifting of drill casing. More particularly, the present invention relates to an apparatus positionable along the first and second ends of a length of drill casing for lifting the section of drill casing substantially parallel to the ground.
2. General Background
In the drilling of oil wells, one of the more necessary components in the drilling process is the need for numerous sections of drill casing which are assembled end to end for forming a casing around the drill string, on the end of which is rotated a drill bit for the drilling of the hole. Each length of drill casing measures approximately a standard length of twenty to forty feet, and weighs up to three to four thousand pounds. It is readily foreseeable in the drilling of a standard oil well, which may go to a depth of thirty to forty thousand feet, that literally thousands of sections of drill casing must be placed end to end. One of the practical problems involved in supplying this drill casing is the transport of the drill casing from one point to another point, for example, from the pipe yard to a transport truck, and from the transport truck perhaps to the drill site, and subsequently on to the drill platform. Often times, this transport is accomplished with the use of a harness or sling which is simply swung around the length of a pipe, and a crane or the like lifts the section of pipe precariously balanced in the sling and positions at its end destination point. It is quite obvious that such an operation is often times dangerous and hazardous to the workers in the area, and requires a great deal of positioning of the sling in order to properly balance the section of pipe so that the pipe does not fall from the sling and cause damage or injury to personnel.
Several patents have been issued which are pertinent to the art, those patents listed in the following columns as follows:
______________________________________ PATENT NO. INVENTOR TITLE ______________________________________ 4,126,347 Hogue PUMP HOUSING SLING 626,350 Tiffany STEVEDORE"S LIFTING HOOKS 991,980 Harper RAIL HANDLING DEVICE 1,021,564 Warnitz HOISTING APPARATUS 2,654,629 Renfroe HORIZONTAL PLATE LIFTING CLAMP 4,359,241 Kistner DRUM HOLDER 3,488,079 Stinchfeld BARREL LIFTERS 4,139,179 Kuklaki HOISTING APPARATUS ______________________________________